test: Add test for `route remove`.

Signed-off-by: Blaž Hrastnik <blaz.hrast@gmail.com>
test: Test out the key commands.

Signed-off-by: Blaž Hrastnik <blaz.hrast@gmail.com>
test: Add test for flynn kill.

Signed-off-by: Blaž Hrastnik <blaz.hrast@gmail.com>